it sounds internal.


spun bearing? piston slap?


what are the symptoms of a spun bearing? I'm hearing a definite metal-to-metal noise from the passenger side, I've got erradic oil pressure (25-60psi, even at steady rpm), smoke coming from dipstick (or steam?), and it has been running like crap lately. I tightened all of the rockers 1/4 turn; I couldn't hear anything over the loud sucking of the TBI, and I don't think it was a tick because I was feeling for looseness and got nothing.

 

I have a sample video of the noise... Idling at about 1000-1200rpm you can distinctly hear it. It's very embarrassing.

http://oej.homestead.com/files/noisyidle.avi

 

OMG... that sounds horrible.

I'm not going to be much help here but if I had to guess, I would say you'r exhaust manifold has either cracked or the manifold gasket has been compromised in some way. That doesn't explain the steam from the dipstick though. I'm afraid to guess what that could be.

What were you doing when this started happening?

Sorry.

 

It's not a cracked manifold/header, and it's not an exhaust leak. I thought it may have been a blown head gasket (between cylinder walls), but it seems way too loud to be that.

and it just started doing this about a week and a half ago.

 

Started happening out of the blue?

 

for the most part, yes. I mean I didn't do anything different to it to cause this.

 

When you remove the valve covers, you don't see anything broken or anything?

 

I'm having trouble loading the sound file over dial-up, but if you're hearing noises and oil pressure is wierd, sounds like bearing damage.

Even though people say it all the time, bearings are rarely "spun". They can be damaged from lack of oil pressure, and since you say nothing unusual happened or was done, it may have been your oil pump that started the problems.

 

you can save it, it's only 1.2MB


no broken springs, no binding, nothing out of place...

 

I gave it ten minutes, then gave up.

I'll try later.

 

I can send it to you via AIM...

 

It's the sound of an engine that needs to be replaced.
Thank your lucky stars that you live in a state that has no smog laws, and your car is powered by a gen1 sbc.
You can pull an engine from anything from a wrecked vette to a dumptruck and it will fit, and you can make it run.

 

Sounds pretty bad, take a short peice of hose and use it like a stethoscope and see if you can determine where the sound is coming from, It sounds like internal engine noise but I have heard a similar noise that was just a loose flexplate.

 

dont run the engine...if it is bearing damage you may do more damage to your hard parts.I would agree thats its bearing damage due to the eratic oil pressure.I'd pull the pan and check there bearings if you can,might find some neet metal figurines in there

 

maybe a collapsed lifter? I didn't feel any play when I was adjusting the rockers this morning...

 

Go to Sears and get a mechanic's stethoscope. You'd be surprised how easy it will make it to isolate noises like exhaust leaks, bearings, rockers, vacuum leaks, etc. Is the noise at engine speed or half engine speed? Remember the crank will spin twice for each rev of the valvetrain. The timing light will flash every other rev, or at half engine speed.

 

So Token... whatcha gonna do?

 

That's not a lifter. It definitely sounds like something in the bottom end.

 

I don't think it's valvetrain. Goes too fast if that engine is running at idle speed. Valvetrain noises are at 1/2 of engine RPM and that just sounds too fast to be something valvetrain related unless it was running at an elevated RPM level when you took the video.

Something in the bottom end went ka-plooey probably (that's the technical term). I would check some obvious stuff first- like did the flywheel/flexplate loosen up or snap a bolt off? That can put up a heckuva racket. Ditto and balancer that's badly wrecked in some way. But given the oil pressure and smoke from the dipstick problems I'm gonna say that short block has gone bye-bye.

 

Did you hit something? May be a huge dent in the oil pan. If not, it'll be the bearings. That's my guess.

 

I can't find where exactly the sound is coming from, but it's not consistent. It does not always make the knocking sound, however for the most part it gets louder with RPM. It does however stay consistent with rpm, making the noise as per the motor turning. I have yet to rule anything out, because I figure if I am going to rip the motor apart I might as well get a new one anyway.

Let's recap the potential problem list:

- At best, it is a collapsed lifter- but I would think that it would be making this noise on a more consistent basis, and I don't know if it would get louder with rpm. This would be the easiest thing to replace, because it's just right under the intake manifold. However, the last time I had the valve cover off I definitely did not notice anything akward such as a loose pushrod. Doesn't mean I won't check again! But you're right, it sounds wayyy too loud to be a valve tick.

- I have been also told it is potentially piston slap, but again I would guess it to be more consistent of a sound. I'm not sure of how common piston slap would be on a 305, however anything is possible.

- With my oil pressure being sporatic, I am lead to believe that it could be a spun bearing. I do not know if there is any contact with the piston to the head, but I would also assume that it's going to be extremely loud, and I would also figure to have bent valves in the process, causing an extreme power loss which I am not experiencing. But then again, what else is possible?

- I was driving this POS to work today, and I had an idea. Could it potentially have anything to do with a flexplate? I've heard stories, but I am not entirely sure how the sound would be made. I think that it's a big gear that's bolted to the crank, correct? But as I said, I am fairly sure that this sound is coming from the passenger side of the engine compartment but not 100%.

I have yet to change my oil due to the fact I have no garage or any place to work on my car, and it's been nonstop rain and snow for the past two weeks. I have checked the color of the oil, and it's definitely black as coffee. I will see if I can borrow a buddy's garage some time this week. It's hard working 40 hours and still trying to function around working on my car, especially when it's dark by 5pm.

How much is a comression tester? Doesn't seem like much money and it would be a great addition to the tool collection. I would use it just by turning the motor one half turn, right? The concept is there, but I'm not familiar with what they look like (other than a hose and guage) or their correct operation.

 

I posted a similar problem yesterday. "...timing ok but Knock/Rattling noise"
Loved the Video/Audio.
I wish I was as technologically advanced.
That is the same noise my car is making.
I had two different guys look at it and they also thought it might be transmission related but it sounds like it is coming from front right side.

Question is if it is Trans related would not the noise change pitch or rhythm when it is put in drive, reverse or under load.

Thanks

 

That is not piston slap. It sounds like death. It may be time to swap those parts on a 350. You may spend less getting a 350 than paying to have this problem diagnosed.

 

The poor car is on its death bed. It's not going to last. It's getting louder every time I drive it.

I am going to see what my dad can do for me (monetarily) and if nothing then I am going to cry and take the city bus everywhere. I'm so sad

 

Where do I go from here?

I could really go for a 350 right now. I'm going to start looking around for one ASAP. And obviously the car in its current condition is fairly worthless, at best $1500 from a dealer trade-in. I want a 4th gen (LT1 M6) really bad too, but I have a ton of parts that would fit a thirdgen for muscle.

I should find a really beat up, ugly L98 thirdgen with 3.xx posi and work on that. I've got auto-body classes this semester...

 

Cam bearings using have a rattling noise to them. Flexplate noises would not cause a oil pressure problem. I'd bet you'll find a rod bearing problem after replacing the engine

 

I just recently had that noise. That my friend, is the sound of a collapsed lifter. I can hear the ticking. Pull the intake and replace the lifters.

 

Would this be causing, or due to, my crazy oil pressure? it goes from 20-60psi just randomly, like the pump is running dry or something. Thing is- there's plenty of oil in there... I even added two quarts just to be sure.

 

Okay, who the hell cares what's wrong with it.

The fact of the matter is, that it is dying within the next 25 miles. I can garauntee this.




I just drove it home from work, and it was getting progressively louder, then the SES light came on and told me to gtfo. I am driving it back to my parents house in a bit, to use as leverage to get a new motor/car/etc from my dad. If that doesn't work, he can at least pay to tow the f*cker away and be burned

 

A cracked flexplate and a "spun" bearing sound the same. But from your description of erratic oil pressure, I am going to have to agree with everyone else that it is a bearing. Has the car overheated any that you are aware of?

 

It almost did, about three weeks ago, and I even made a post about it. The coolant mix was off, and froze.

 

Just for peace of mind try a new Oil pressure switch. $30.00
Mine was jumping 20-60 replaced and now reads good 60-65.
It also fixed a mysterious oil leak I couldnt find.

 

I agree with Formula75 - can't hurt to try a new switch just to be sure that's not the source of the fluctuating pressure. IF it is, then the rest may not be so serious/expensive to fix.....

 

Did you not hear the video?

 

Nope - they're blocked from downloading here (paranoid employer) sorry - I'll go back to sleep/lurking again....

 

I finally was able to get it to play.

Too much talking over the noise. And, it would be helpful to hear it at varying RPMs as well.

But, sounds like either a really bad lifter or a rod bearing.

 

I have other videos just no where to host them.

 

Thats a bearing noise. Don't worry about the oil pressure switch, that engine is F'd in the A$$

 

token, how big is the file? i can host it for you... just PM me with the size of the video

 

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4.23mb though

 

Token,

My car is making the same noise. Its an 84 305 with automatic transmission.
I can not afford a new engine or professional diagnosis.
Some repliies to your question said flexplate and others said no because of flucuating oil pressure.
I think Oil pressure is a seperate issue.
Try the oil pressure switch, quick and easy fix.
I am going to drop my transmission this weekend. I am being told where the flex plate mounts to the crank is where it would be cracked.
You can not see that just by removing the dust cover.
I will let you know monday what I find.

Formula75

 

thats a big file for me to host off my dsl... but send it to me at djhafownz@cofs.net in a zip file and ill host it for you. later

 

Have you guys checked you flexplates yet?

 

nah, it's FAR too loud to be a flexplate, I'd think.


I don't have a garage, there is 6" of snow out, and my doors are frozen shut. I think the car is fine just not being touched lol.

 

Kinda sounds like something valve train related to me... but if the oil pressure is going nuts its gotta be a bearing problem.

All the "rods knocks" i've heard sound much deeper and arent quite as, whats the word? melodic? Rather than going ticktickticktickticktickticktick along with the RPM it'd go like "clacktick----cliclclickticktick---tick---clickc---tickkk-----clackalclack"

I dont think it'd hurt to pull off the valve covers again and check over all the springs, studs, rockers, and pushrods then if they're alright time to take off the intake and check out the lifters... Also might be able to give you an idea by pulling out the dipstick and rubbing the oil onto your fingers. Is it grity or have any metal particles in it?


Anyway, this thread could go on forever of what the sound might be, the only way you're going to figure it out is by tearing it apart. Start wrenchin' what do you have to lose that you dont already think is lost?

 

Clogged cat? it is on that side of car. Steam from the dipstick tube is prob just because as you say it's freaking cold.

 

Today, the motor seized up and died.
I'm not sure if it blew anything apart or if it just stopped stroking, but in any case it's dead and now is on the market for sale. ENJOY!


Thanks for those who helped, and who mourn my loss

 

so it died, go buy a 305 short block for 50 bucks and replace it. Or any number of sbc's to fit under it. You could make it run for a couple hundred dollars AT MOST and not get slaughtered on the re sale.

I sold a car a few years ago for 300 dollars because it died and i was to lazy to figure out what was wrong. I took a major loss on it and it turned out to be a 30 dollar timing belt.

 

Pull the engine and put it under your pillow before you go to bed tonight

Motor ferrry might be generous

 

That sucks